DESCRIPTION: (Investigator?s Abstract): This is a proposal to establish a comprehensive DNA Microarray Analysis and Bioinformatics System at the University of Kentucky. DNA microarray methods clearly will revolutionize future studies of gene expression. Numerous NIH-supported projects here already focus on gene expression and regulation approaches, in many cases with transgenic animals. Therefore, the ability to incorporate large-scale gene array analyses would vastly accelerate progress, refine interpretation, and drive the discovery of novel expression-function correlations in these projects. At present, expression analyses are performed here with slow, labor-intensive and/or limited methods (e.g., PCR, small chips, Northerns, etc.). Gene array capability would also be of particular benefit at Kentucky because many of the major users? projects emphasize quantitative comparisons and detection of subtle differences in gene expression (e.g., with aging, exposure to growth factors, hormones or toxicants, brain injury, circadian rhythms, carcinogenesis, signaling cascades, etc). The integrated system requested here (Affymetrix), is the only fully comprehensive system (chips, hybridization oven, fluidics station, laser analyzer, bioinformatics package) presently available, and several of our faculty are experienced in its use. This system also appears to be the most sensitive, accurate and standardized, characteristics that would be a key benefit to the quantitatively oriented projects at the University of Kentucky. In addition, several of the projects at Kentucky are developing and refining novel methods for expression studies in functionally characterized single orhomogenous cells in order to more accurately study correlations between expression and function. A component of this work involves the representative amplification of sufficient quantities of mRNA to allow expression profiling in single cells. Development of these approaches would be greatly facilitated by gene array profiles that could provide detailed information on how representative and reproducible the various amplification procedure are. Thus, the proposed system would not only specifically enhance progress in multiple NIH-funded projects at the University of Kentucky, but would facilitate the development of new methods that may well benefit investigators at many other institutions as well.